Rework status validations

[adamtagscherer]

Problem

There are multiple API objects (resource clean up, asset scan, asset scanner and there will be a new one with the multi cloud feature) that have a status field which is used to determine the resource's health/availability/etc.
The format for the status field is not unified therefore they have to be threated differently when it comes to validation, state transition, etc.
Also currently it is possible to set an asset scan's from Done to Scheduled because there is no validation on it.
It would be better to have a unified data structure for all the status fields.

Solution

API model for status

CommonStatus:
  type: object
  properties:
    reason:
      type: string
      description: Machine readable message.
    message:
      type: string
      description: Human readable message.
    lastTransitionTime:
      type: string
      format: date-time

With the Status object and the allOf openapi directive we will be able to create the Statuses for the different API objects.

AssetScanStatus:
  allOf:
    - $ref: '#/components/schemas/CommonStatus'
    - type: object
      properties:
        state:
          type: string
          enum:
            - Pending
            - Scheduled
            - ReadyToScan
            - InProgress
            - Aborted
            - Failed
            - Done

Status transition validation on go code level

type AssetScanStatusState string

// Defines values for AssetScanStatusState.
const (
    AssetScanStatusStateAborted     AssetScanStatusState = "Aborted"
    AssetScanStatusStateDone        AssetScanStatusState = "Done"
    AssetScanStatusStateFailed      AssetScanStatusState = "Failed"
    AssetScanStatusStateInProgress  AssetScanStatusState = "InProgress"
    AssetScanStatusStatePending     AssetScanStatusState = "Pending"
    AssetScanStatusStateReadyToScan AssetScanStatusState = "ReadyToScan"
    AssetScanStatusStateScheduled   AssetScanStatusState = "Scheduled"
)

type StateMachine map[AssetScanStatusState][]AssetScanStatusState

var validTransitions = StateMachine{
    AssetScanStatusStatePending: {
        AssetScanStatusStateScheduled,
    },
    ...
}

func (s *AssetScanStatus) Update(to AssetScanStatusState) error {
    transitions := validTransitions[*s.State]
    for _, t := range transitions {
        if t == to {
            s.State = &to
            return nil
        }
    }
    
    return fmt.Errorf("invalid transition, from: %s to: %s", *s.State, to)
}

// Usage in the asset_scan_controller.go
func (s *ServerImpl) PatchAssetScansAssetScanID(ctx echo.Context, assetScanID models.AssetScanID, params models.PatchAssetScansAssetScanIDParams) error {
    ...
    existingAssetScan, err := s.dbHandler.AssetScansTable().GetAssetScan(assetScanID, models.GetAssetScansAssetScanIDParams{})
    err = existingAssetScan.Status.Update(*assetScan.Status.State)
    if err != nil {
        return sendError(ctx, http.StatusBadRequest, err.Error())
    }
    ...
}

[Tehsmash]

One suggestion here is that the common schema be called something like "CommonStatus" so that its obvious that its supposed to be a "base" type not a schema to be used directly.

[adamtagscherer]

thanks for the feedback, we can go with that name for sure

[chrisgacsal]

Agreed with @Tehsmash.

[chrisgacsal]

Thanks @adamtagscherer for putting this proposal together. I am very much in favor of this being implemented. LGTM!

[ramizpolic]

Already done